AS Sarah from LLL might say, you will always have enough milk when breastfeeding. I expressed milk for my baby for 10 months and she was breastmilk-fed exclusively for the first 6 months.
What I do suggest is to pump and save for the first few months when the baby will not need so much milk, so you can easily store (plus it will help engorgement). I used the mini electric when I went out and then the Symphony when I pumped at home (the symphony does both breasts at the same time so was good for someone like me who needed to pump 8 times a day), but I also like the mini electric. Both are by Medela.
For the bottles, Adiri can be sterilised using boiling water but with sterilisers, you need to be careful as some heat up to be above 100 degree and will ruin the bottles. When boiling them, I put a towel around the edges of my pot so that the plastic bit do not touch the metal bits, I do this with my heat pads which I used for warming up my breasts before pumping too (warming up helps me get more milk it seemed).
As for the life of the bottles, it suggests 3 months as the bottles comes in 3 sizes (Stage 1 for up to 3 months old; Stage 2 for 3 -6 months; and Stage 3 for 6 months up), this actually is the same for other bottles where you change the nipples every 3 months. This is for the reason of both the flow rate and also hygiene.
I would suggest that you just get Stage 1 to begin with and go from there (or Stage 2 if you think you will only start bottle feeding after 3 months).
Seriously, do not worry about not having enough milk supply, as long as you are letting the milk out, through the baby sucking or pumping, your breast will make enough milk. For me, at first, I only have like 30ml a pump making a total of around 250ml a day, but that was also how much my baby needed then! At the peak, I was pumping a litre a day even though my baby didn't drinnk that much, I really felt like a cow!!! As my baby began on solids, her needs went down again and so did the supply (also because I became a little lazier and pumped only 3-4 times a day) but she still had enough.
Breast milk is the best you can give to the baby, so good luck and I would gladly help anyone with questions. I also suggest for all first time mothers-to-be to attend LLL's tea breaks and meetings (they are all free) but it was SOOOOO helpful to have support of the leaders and also share problems and solutions with other mothers going through the same thing. We also got practice breastfeeding in public (together! haha) at Starbucks.
